Combined pressure compensator and cooling unit

ABSTRACT

A container for containing underwater sensors such as sonar transceivers, sonar imaging devices, optical imaging devices, etc, electronic equipment and a cooling liquid for cooling the electronic equipment is connected to a second, variable volume container which acts both as a heat exchanger and as a pressure compensator for compensating the pressure difference between the cooling fluid and the surrounding water or other fluid.

FIELD OF THE INVENTION

The field of the invention is the field of electronics for underwater sonar, sonar and/or optical imaging, and other underwater data and computationally intensive operations.

BACKGROUND OF THE INVENTION

A prior art underwater sonar apparatus is shown in FIG. 1. A container 10 contains electronic equipment 12 in a coolant fluid 14. The electronic equipment 12 is connected through a connection (not shown) to a sonar transceiver 16, an optical imaging apparatus, or other apparatus for investigation of the surroundings of the container 10. The container 10 is attached to a ship or to a remotely operated vehicle (ROV) and used to investigate the sea objects therein in the vicinity of the ship or ROV.

RELATED PATENTS AND APPLICATIONS

The above identified patents and patent applications are assigned to the assignee of the present invention and are incorporated herein by reference in their entirety including incorporated material.

OBJECTS OF THE INVENTION

It is an object of the invention to produce an apparatus and method for cooling electronic equipment which is immersed in water or other liquid which can act as a heat sink for the heat produced by the electronic equipment. In addition, the apparatus compensates for the pressure variations between coolant liquid cooling the electronic equipment and the surrounding water.

SUMMARY OF THE INVENTION

A variable volume container is used to transfer heat through the container walls from the coolant cooling electronic equipment to the water surrounding the apparatus of the invention. When the pressure in the coolant rises because the coolant temperature rises, the volume of the container changes to compensate the pressure change.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sketch of a prior art apparatus for underwater sonar imaging.

FIG. 2 is a sketch of the prior art apparatus when pressure of coolant fluid

FIG. 3 is a sketch of the most preferred embodiment of the invention.

FIG. 4 is a sketch of the most preferred embodiment of the invention when pressure coolant fluid within the container containing electronic equipment rises higher than the pressure of outside cooling water.

FIG. 5 is a sketch of a preferred embodiment of the invention.

FIG. 6 is a sketch of a preferred embodiment of the invention.

FIG. 7 is a sketch of a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A container 10 contains electronic equipment 12 in a coolant fluid 14 in the prior art sketch of FIG. 1. Heat generated by the electronic equipment 12 and transferred to the coolant fluid 14 is conducted through the walls of the container 10 to the outside water or other fluid 18. The electronic equipment 12 is connected through a connection (not shown) to a sonar transceiver 16, an optical imaging apparatus, or other apparatus for investigation of the surroundings of the container 10. The container 10 is attached to a ship or submarine, to a remotely operated vehicle (ROV), or to an automated underwater vehicle (AUV) and used to investigate the undersea objects therein in the vicinity of the vehicle.

FIG. 2 shows a sketch of the apparatus of FIG. 1 when the coolant liquid 14 is heated and expands. The distortion of the container 10 is exaggerated in FIG. 2 for clarity. However, the distortion is sufficient to change the orientation of sensor 16 with respect to container 10 and to the ship or ROV mounting the container 10. In addition, the material and walls of container 10 must be much stronger and thicker to withstand the stress needed to hold the pressure of the fluid 14. The thicker walls mean that the heat transfer coefficient for transferred from the coolant fluid is reduced, and so that the temperature and thus pressure of the coolant fluid must rise yet further.

FIG. 3 shows a sketch of the most preferred embodiment of the invention. A second container 30 is attached with a fluid connection to the first container 10. In the embodiment shown, the coolant fluid circulates through the inside of container 10 and the inside of container 30, and heat is transferred through the walls of container 10 and container 30 to the surrounding cooling water 18. Of course, the apparatus of the invention may be used for heat exchanging the heat from the coolant liquid to another liquid besides water.

FIG. 4 shows a sketch of the apparatus of FIG. 3 when a large heating load is generated by the electronic equipment 12. The volume of the second container 30 increases to contain the increased volume of the heated cooling fluid 14. The walls of the second container 30 can now be made very thin, which will make them very flexible and able to increase the volume of the container 30 with little extra cooling fluid pressure over the pressure of the outside water. In addition, the thin walls cut down on the thermal resistance and increase heat transfer. In a preferred embodiment of the invention, the volume of the second container 30 increases by 2% before the pressure inside container 10 is sufficient to distort container 10 unacceptably or to stress the material of container 10 to unacceptable limits. In a more preferred embodiment of the invention, the volume of the second container 30 increases by 5% before the pressure inside container 10 is sufficient to distort container 10 unacceptably or to stress the material of container 10 to unacceptable limits. In the most preferred embodiment of the invention, the volume of the second container 30 increases by 10% before the pressure inside container 10 is sufficient to distort container 10 unacceptably or to stress the material of container 10 to unacceptable limits.

Optional pumps 40 are shown which can circulate coolant fluid from the inside of container 10 through the inside of container 30 and increase cooling of the cooling fluid 14. The flow of cooling water is depicted by the arrow 42.

Note that if the apparatus of FIG. 3 is used at great depths, the volume of the second container 30 can decrease to compensate for any compressibility of the cooling fluid 14.

FIG. 5 shows a preferred embodiment of the invention, wherein the second container 30 is contained within the first container 10. In this case, the cooling water circulates within the second container 30, and the coolant liquid 14 is outside the second container 30. In the case that the coolant fluid is heated and expands, the volume of the second container 30 is reduced to compensate for the pressure change. An optional scoop is shown to move the outside water or fluid through the second container 30 and increase cooling of the cooling fluid 14.

FIG. 6 shows an embodiment of the invention having simple construction and assembly. An array of tubes 60 are inserted through holes in the container 10, and provide a heat exchanger for exchanging heat between the coolant fluid 14 and the outside water. Optional funnels 62 are shown for funneling outside water through the tubes 60. If the tubes have thin walls, the heat transfer is maximized and the volume of the tubes will be reduced to compensate the pressure changes within the container 10.

FIG. 7 shows a sketch of a preferred embodiment of the invention, wherein the container 30 is a bellows 70 which allows great expansion with modest pressure difference between the coolant fluid 14 and the surrounding water. An optional external shroud 72 is used to protect the bellows 70, and to provide a channeling flow for the water circulation, as depicted by the arrows

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. 

1. An apparatus, comprising: a first container for containing electronic equipment, wherein the electronic equipment is immersed in a liquid coolant, and wherein the apparatus is for immersing in water; a second container for transferring heat from the liquid coolant to the water, wherein the volume of the second container varies to compensate pressure differences between the liquid coolant and the water.
 2. The apparatus of claim 1, wherein the second container is contained within the first container, and wherein the water communicates between the inside of the second container and the outside of the first container.
 3. The apparatus of claim 2, further comprising means for flowing the water through the inside of the second container.
 4. The apparatus of claim 3, wherein the means for flowing is a scoop.
 5. The apparatus of claim 3, wherein the means for flowing is a pump.
 6. The apparatus of claim 2, wherein the second container is a pancake shaped container.
 7. The apparatus of claim 2, wherein the second container is a bellows.
 8. The apparatus of claim 1, wherein the second container is located outside the first container, and wherein the liquid coolant communicates between the inside of the first container and the inside of the second container, and wherein the water outside the first container and the outside of the second container cools the liquid coolant inside the second container.
 9. The apparatus of claim 8, further comprising a pump for circulating the liquid coolant between the inside of the first container and the inside of the second container.
 10. The apparatus of claim 8, wherein the second container is a pancake shaped container.
 11. The apparatus of claim 8, wherein the second container is a bellows.
 12. The apparatus of claim 1, wherein the second container is a pancake shaped container.
 13. The apparatus of claim 1, wherein the second container is a bellows. 